Process of manufacturing gas.



No. 680,784. Patented Aug. 20, I90]. W. J. KNUX.

PROCESS OF MANUFACTURING GAS.

(Application filed Nov. 12, 1900.)

(No Model.)

WITNESSES: 1 IN VE/V TOR ATTORNEY.

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XVILLIAM JOHN KNOX, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO GEORGEWESTINGHOUSE, OF SAME PLACE.

SPECIFICATION forming part of Letters Patent No. 680,784, dated August20, 1901. Application filed November 12, 1900. Serial No. 36,265. (Nospecimens.)

To all whom, it may concern.-

Be it known that I, WILLIAM JOHN KNOX, a citizen of the United States,and a resident of Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inProcesses for the Manufacture of Gas, of which the following is aspecification.

My invention relates particularly to a process forthe manufacture ofgas, the invention being especially useful for the economical andeiiicient continuous process of producing gas. The broad features of theinvention have, however, a wider application than to gas processes, aswill be hereinafter pointed out.

The general plan of my invention is to maintain the requisitetemperature in the gasproducers or other reacting vessels by circulatingtherethrough large quantities of gas heated to a proper temperature andto cause those portions of the system in which a coniinuous operativecondition cannot be constantly maintained to be restored to theiroperative condition during the time that other portions of the systemare in productive operation and to efficient-ly conserve the heatdeveloped.

In another application filed by me October 5, 1900, Serial No. 32,115, Ihave described and claimed certain features which are described herein.In that application claims are made to the method of producing gas inwhich a heated volume of gas is passed into a producer, and the volumeof gas is thus augmented and passed through a steam-generator, portionsof the gas being withdrawn and i the remainder reheated andrecirculated, and in another application, Serial No. 36,269, filedNovember 12, 1900, claims are made to apparatus for carrying out theprocess above referred to. In still another application filed by meNovember 14, 1900, Serial No. 36,443, claims are made to the apparatusdescribed herein.

The construction of the system and its operation will be described inconnection with the accompanying drawings, in which Figure 1 is adiagram showing the general arrangement of the apparatus and thecirculation of the gases during one stage of the operation. Fig. 2 is asimilar diagram showing the circulation of the gases during a succeedingstage of the operation.

Referring to the figures, A A A A represent stoves of any suitablecharacter, such as are usually employed in gas-prod ucing apparatus forheating gases. They are provided with suitable briclc surfaces forimparting the heat which has been previously stored in them by thecombustion of fuel therein to the gases when they are circulatingtherethrongh. The special construction of these stoves forms no part ofthe present invention, inasmuch as any efficient form of stove may beemployed.

Two producers are represented at B and B of any suitable well-knownconstruction, and are connected together at their bottoms bya passage b.One end of each of the stoves A and A is connected with a pipe (1,leading to the upper end of the producer B. Corresponding ends of thestoves A A are connected with the pipe a which leads to the top of theproducer B The ends of the stoves which are thus connected with thepipes a, 0, will be, for reasons which will presently appear, referredto in this specification as the hot ends of the stoves. The oppositeends of the stoves A A called the cold ends, are connected by a pipe awith a steam generator or evaporator E, and the cold ends of the stovesA A are connected by a pipe at with a similar steam generator orevaporator E The steam-generators E and E are connected with each otherby means of a pipe a through a suitable fan or blower F. They are alsorespectively connected by pipes a and a with a scrubber and water sealO, which is provided with an outlet-pipe a designed to lead to agas-holder or other suit able apparatus for receiving or consuming thegas.

For con ven ience in describing the operation of the apparatus it willfirst be assumed that the circulation of the gases therethrough has beenestablished in some convenient manner.

Referring now particularly to Fig. 1, the stove A is hot, having beenpreviously heated by the combustion of fuel in a manner well understood.This fuel may be either a. quantity of gas produced in the system orobtained from an outside source. A quantity of gas derived from theproducers is forced by the fan F through the steam-generator E, thencethrough the pipe a to the cold end of the stove A, out through the hotend, thence through'the pipe at to the upper end of the producer B. Asuitable supply of steam is added to the gas from the evaporator Eeither before it enters the producer or within the producer, as foundconvenient. \Vhen the steam comes in contact with the coke with whichthe producer B is charged, water-gas is produced in the usual manner.The augmented volume of gas from the bottom of this producer B passesthrough the pipe 6 to the bottom of the producer E which is beingcharged with bituminous coal. This gas is still very hot and passingupward through the producer B it distils the hydrocarbons from the coal,gradually reducing it to coke. The water-gas, with the added hydrocarbongases, then leaves the producer B at its upper end and passes throughthe pipe a to the hot end of the relatively cold stove A Thisstove,however, still retains more or less heat, because of its havingbeen a hot stove in the previous operation. The gases passing into thehot end and out of the cold end of this stove lose much of their heat asthey go, and the hydrocarbons passing over the hot bricks will be fixedinto permanent gases. They pass thence to the steam generator orevaporator E by way of pipe at", where much of the remaining heat isutilized in raising steam for making the water-gas. The fan F meanwhileis being operated in any convenient manner to force the gases forwardthrough the pipe a and the steam-generator E. A portion passes out ofthe system through the pipe a and the water seal 0, the pipe or beingmeanwhile closed by a valve 0 The balance of the gas passes on to thestove A and repeats its cycle, as already described. This operation iscontinued, more gas being constantly produced than is circulated, theexcess passing off to the holder until the stove A has become cooledbelow the eflicient gasmaking temperature. As the coke in the producer Bis gradually consumed coal is added to the top of the producer 13 sothat at the end of the run the producer B is empty and the producer B isfilled with coke, its charge of coal having been now reduced to coke.The direction of the fan F is then reversed, the valve 01 in the pipeleading from the cold end of the stove A to the pipe or is closed, thevalve 01 in the pipe leading from the stove A to the pipe at is opened,the valve 0 in the pipe a is closed, and the corresponding valve 0 inthe pipe at is opened. Then the circulation will be,as shown in Fig. 2,from the fan through the stove A down through the producer B now chargedwith coke, up through the producer B, which is being charged with coal,thence through the relatively cold stove A and the pipe a to thesteam-generator E, thence through the fan and the steam-generatorE aportion then passing out through pipe a and the remainder continuing thecirculation. Meanwhile the stoves A and A are being brought to a hightemperature by the combustion of fuel,

each stove being heated during the two previous runs. In the next cyclethe stoves A and A will be in use and the stoves A and A will beheating. The continuation of the process, whereby each stove is used .insuccession as the heating-stove and as the fixingstove, will be apparentfrom the description already given.

It may be stated in general terms that the economy of the system isdependent upon the lowness of the temperature of the escaping productsof combustion of the fuel employed in heating the stoves, and it istherefore especially important that the temperature of the cold end ofthe stoves from which the products of combustion of fuel employed forheating them escape shall be at all times as low as practicable. Forthis reason the gases which are circulated through the stoves to theproducers should be cooled before passing into the stoves, for the coldends of the stoves will have the temperature of the gases entering them,and thereafter when the stove is being heated by the combustion of fuelthe products of combustion will have their heat absorbed in the stoveuntil they reach the cold end and, passing out to the flues, will be ofpractically the same temperature as the cold end. culated directly fromthe producer to the heating-stove without being cooled, then the coldend of the heating-stove would be raised in temperature to such anextent that when the stove was afterward being heated up by thecombustion of fuel the outgoing products I of combustion would be atsuch a temperature as to carry off and waste an excessive amount ofheat.

The heat which is taken out of the gases by the steam-generators is notlost, butis stored up in the steam, and thus is retransferred to theproducers. That portion of the gas which is being constantly drawn offand passed to the holder is still further cooled by passing through thescrubber O, and the hot water may be pumped from this scrubber to thesteam-generators E E In general it is desirable that the outgoing end ofthe producer should be kept at as nearly the same temperature as itsingoing end as practicable. Therefore the temperatures of the gasespassing from a producer must be high, and hence it follows that thestoves and steam-generators must be so organized as to absorb as much aspossible of this heat and deliver it back again in some form to theproducer. If it were practicable to so make the producer that the gasesshould leave it at a low temperature, then it would not be necessary topass the gas through a steam-generator or other heatconserver, for itcould then be made to enter the end of the heating-stove at the minimumtemperature, and thus keep that end of the stove cool.

The stoves, on the contrary, should, for the reasons already given, beas cool at the cold end as practicable and suiiiciently hot at the Ifthe gases were cir-.

other end to give the requisite temperature to the producer, and,furthermore, by having one end cold and the other hot they give offtheir heat to the gas passing through them in an economical manner,because the difference in temperature between the gas and the surfacesof the brick with which they come in contact is approximately a constantfac tor throughout the entire length of the stove, and thus the stoveyields heat uniformly to the gas throughout its entire length.

It has been heretofore proposed to superheat steam outside of theproducers and to use the steam not merely as a constituent for formingwater-gas, but also for conveying into the producer sensible heat fordelivery to the producer; but the heat which it is practicable to carryinto the producer by means of the steam alone as a carrier is notsufficient to replace the heat absorbed by the chemical change requiredto produce watergas. It has also been proposed to carry heat into theproducer by circulating therethrough quantities of the produced gaspreviously heated by stoves. I secure the heat required by usingsufliciently-large volumes of pro duced gas heated to the propertemperature and mingled with the heated steam to act as a carrier forthe heat-units required to convert the entiremass of coke and its equivalent of steam into water-gas when once the operation has commencedwithout the neces sity of stopping the operation and the reheating ofthe coke by other means.

By mingling the gas and the steam together, and thus diluting the steambefore attacking the coke, I secure a very important result namely, anincrease in the rate of dissociation. The steam is more evenlydistributed throughout the entire mass of the coke, and because of themechanical separation of its molecules by the gas the decomposition andthe formation of the water-gas is more rapid and is also effected at alower temperature than is required when pure steam is e1nployed. Thisresults, therefore, not merely in the more even and rapid formation ofthe water-gas and even temperature on the part of the coke, but it alsorenders it possible to Work with lower temperatures than where steamalone is employed. The reduction in temperature thus secured is afeatureof much importance, because the higher the temperature dealt with thegreater is the difficulty experienced with the valves and other parts ofthe apparatus.

By passing large quantities of heated gas mingled with the steaminto'the producer containing coke the temperature at the outgoingterminal can be maintained very nearly the same as that at the ingoingterminal, and thus the heat of the circulating gas and the newlyproducedwater-gas as it passes to the producer containing coal is sufficient tooperate very effectively upon the coal and distil out the hydrocarbons.It should be noted also that as the coke is gradually reduced .by thethere is an approximately uniform amount of coke exposed to the actionof the steam for the formation of water-gas, and when the coke in thefirst producer has been practically consumed the coal in the secondproducer is practically all reduced to coke, and this will be still veryhighly heated owing to the heatcarrying capacity of the circulating gas,so that the latter producer is now in proper heated condition for beingused as a watergas producer when the direction of the current of gas andsteam is reversed.

In the foregoing description I have referred to the apparatus asincluding economizers E E in the circuit. I wish to have it distinctlyunderstood, however, that it is not always necessary to employeconomizers or steamgenerators, such as E E for byproperly proportioningthe stoves A A the stoves themselves may be made to abstract from thegas and to conserve sufiicient of the heat to render the apparatushighly economical and efficient without the aid of the supplementaldevices or steam-generators E E It will be now understood that byincreasing the size of the stoves the temperature of the gas passingthrough a stove from the producers may be lowered in the stove to such adegree that it will pass out from that stove at the desired lowtemperature and the cold end of each stove maintained at the requisitetemperature. It will be understood, further, that whether thesteam-generators E E are used or not the stoves A A act as economizers.One way of viewing the economizers E E is to regard them as extensionsof the stoves, although they have the additional function when used ofgenerating steam.

In some uses of my invention steam may not be necessary, and even incases where steam is necessary I sometimes prefer to supply the steamfrom a separate source and omit the steam-generators E and E. Forinstance, in using the invention for the generation of water-gas fromwood, garbage, &c., containing water in any form the material beingconverted will furnish the necessary steam to the system. Again, in someoperations to which the invention is applicable steam is not necessaryas, for instance, in the production of bituminous gas and in theproduction of carbonic-acid gas from limestone. In this latter case thefundamental principle of operation is essentially that alreadydescribed, limestone being placed in the producers and heat beingconveyed by a circulation of the evolved gas, and the circulating gasbeing raised to its maximum and reduced to its minimum temperaturethrough the heat cycle, a portion being drawn off corresponding to thatgiven off in the producers or reacting vessels. It is also to beunderstood that two producers B B are not always necessary as a singleproducing device may be IOU , excess of heat from the reacting vessel,then raising the gas again to its maximum temperature, and also thereversal of this operation, whereby the heating device becomes theheat-absorbing device and the former heat-absorbing device becomes theheating devicefthe heat which has been stored up therein being yieldedback to the circulating gas. It should be noted that it is advantageousthat the two heating or heat-absorbing devices should be ofapproximately equivalent capacities to obtain the best results.

The invention claimed is 1. The hereinbefore-described method ofmanufacturing gas, which consists in forcing heated gas and steamdownward through a coke containing producer and upward through acoal-containing producer, thereby generating water-gas in the first anddistilled gas in the second producer, thereby consuming coke in thefirst-named producer and producing coke in the second-named producer,and periodically reversing the direction of circulation therethrough.

2. The hereinbefore-described method of manufacturing gas which consistsin forcing heated gas and steam downward through one producer containingcoke, and upward through a second producer containing coal, consumingthe coke in the first-named producer in the formation of water-gas,transforming coal into coke in the second-named producer by theformation of distilled gas.

3. The method of manufacturing gas which consists in forcing heat-ed gasand steam downward and upward, respectively, through two connectedproducers and generating water-gas in one and distilled gas in theother, and periodically reversing the direction of circulation.

4. The hereinbefore-described process of manufacturing gas whichconsists in heating a portion thereof to a high temperature,transmitting the same through a producer, artificially cooling the gasto a mimimum temperature, conserving the heat thus artificiallyWithdrawn, withdrawing a volume of gas approximately equal to that beingdeveloped in the producer, reheating the balance to a maximumtemperature and repeating the cycle.

5. The hereinbefore-described process of manufacturing gas whichconsists in alternately raising to a maximum temperature and cooling toa minimum temperature a determined Volume of the produced gas, andcirculating the same through the producer at its maximum temperature andinto the heater at its minimum temperature.

6. The .hereinbefore-described process of producing gas, which consistsin circulating a predetermined amount of gas through a heatingapparatus, delivering the same to a producer, simultaneouslysupplyingsteam to the producer, generating in the producer additional gas,cooling the gas as it passes from the producer, conserving the heat thusabstracted from the gas, forcing a portion thereof to repeat thebefore-described circulation, and consuming a portion of the gas toreheat the circulating portion.

7. The hereinbefore-described process of generating gas, which consistsin heating a portion thereof and circulating the same through a producerand cooling devices,thereby alternately raising the same to a maximumtemperature and cooling it to a minimum temperature, and utilizing aportion thereof to develop heat and storing such heat at one point whilepreviously similarly stored heat is being utilized at another point forraising gas to its maximum temperature.

8. The method of conveying heat by means of gaseous fluids, whichconsists in alternately raising to a maximum temperature and cooling toa minimum temperature a determinate volume of gaseous fluid, bycirculating the same through a heating device, thereby giving to ititsmaximum temperature, delivering the same to the apparatus to be heated,then positively cooling the gas, thereafter reheating it, and repeatingthe cycle.

9. The method of conveying heat by means of gaseous fluids through aclosed system, and conserving heat in the system, which consists incirculating the volume of gas through the system, heating the gas at onepoint, utilizing a portion of the heatat another point, cooling the gasat a third point, conserving the heat thus abstracted from the gas atthe third point, passing the cooled gas to the heating-point, andcontinuing the circulation.

10. The method of conveying heat by means of gaseous fluids through aclosed system and conserving heat in the system, which consists incirculating the volume of gas through the system, heating the gas at onepoint, utilizing a portion of the heat at another point, cooling the gasat a third point, conserving the heat thus abstracted from the gas atthe third point, passing the cooled gas to the heating-point andcontinuing the circulation, and periodically reversing the direction ofthe circulation of the gas and coincidently reversing the position ofthe heating and cooling points.

Signed at Pittsburg, in the county of Allegheny and State ofPennsylvania, this 7th day of November, A. D. 1900.

WILLIAM JOHN KNOX.

Witnesses:

J. A. ADAMS, R. J. BRATTON.

